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Plasmonic Waveguide Lithography for Patterning Nanostructures with High Aspect-Ratio and Large-Area Uniformity

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Plasmonic Waveguide Lithography for Patterning Nanostructures with High Aspect-Ratio and Large-Area Uniformity Plasmonic Waveguide Lithography for Patterning Nanostructures with High Aspect-Ratio and Large-Area Uniformity by Xi Chen A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Applied Physics) in the University of Michigan 2018 Doctoral Committee: Professor L. Jay Guo, Chair Professor Julie Biteen Professor Roy Clarke Professor Cagliyan Kurdak Professor Ted Norris Xi Chen [email protected] ORCID iD: 0000-0002-3451-7310 © Xi Chen 2018 ACKNOWLEDGEMENTS First and foremost, I wish to express my sincere gratitude to my advisor, Prof. L. Jay Guo, for his patient guidance and mentorship throughout my Ph.D. study and for suggesting various topics of research. I also appreciate his continuing optimism and his ability to always highlight the positive. He has always been willing to give me great freedom to explore new ideas, and offer plenty of opportunities for both internal and external collaborations. This work would not have been possible without his unfailing inspiration and immense knowledge. His instructions and continuous encouragement kept me motivated and will also remain so in the future. I would also like to thank my committee members, Prof. Julie Biteen, Prof. Roy Clarke, Prof. Cagliyan Kurdak, and Prof. Ted Norris, for their guidance and serving on my committee. Their insightful comments and encouragement motivated me to improve this work from various perspectives. I am also grateful to many current and former group members, for their discussion and help throughout my study. I would like to thank my mentors and collaborators, Dr. Fan Yang, Dr. Cheng Zhang, Dr. Gaofeng Liang, Dr. Jing Zhou, Sung Ho Lee, Qiaochu Li, Darwin Cordovilla, Dr. Long Chen, Dr. Joong Hwan Bahng, Chengang Ji, Qingyu Cui, Sangeon Lee and Zeyu Lei, etc., without whose help I cannot complete these projects. Particularly, I'd like to acknowledge the collaborations with Dr. Fan Yang and Dr. Cheng Zhang on the lithography experiments, Dr. Gaofeng Liang on the roughness analyses, Dr. Jing Zhou on the enhanced Mie scattering and thermal radiation of hyperbolic metamaterials, Sung Ho Lee on the development of the plasmonic roller system, Dr. Long Chen and Zeyu Lei on the enhanced photoluminescence. In addition, my thanks must go the technical support of the Lurie Nanofabrication Facility (LNF), especially the ii following staff members for their continuous assistance: Matt Oonk, Shawn Wright, Dr. Vishva Ray, Brian Armstrong, David Sebastian, Dr. Pilar Herrera-Fierro, Robert Hower, Kevin Owen, Steven Sostrom, Dr. Sandrine Martin and Dr. Nadine Wang etc. I would like to acknowledge the financial support from Samsung Advanced Institute of Technology, National Science Foundation (NSF) and Center for Photonic and Multiscale Nanomaterials (CPHOM). It has been an amazing and rewarding experience to study and at the University of Michigan, especially in Applied Physics program and Electrical Engineering and Computer Science (EECS) department. This is a place full of unending inspirations and unbounded resources. Last but not least, I would like to express my deepest gratitude to my husband Lin, for his love and patience, and for proof-reading this dissertation. My deepest appreciations also go to my family and my friends, especially my parents, for their unconditional love and support throughout this program and my life. Their company gives me the confidence to try anything and the fortitude to see it though. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................................ ii LIST OF TABLES .......................................................................................................................... x LIST OF FIGURES ....................................................................................................................... xi ABSTRACT ................................................................................................................................. xvi CHAPTER 1 Principle of Plasmonic Lithography ........................................................................ 1 1.1 Introduction to lithography and resolution limit ................................................................... 1 1.2 Plasmonic lithography .......................................................................................................... 5 1.2.1 Superlens system ............................................................................................................ 9 1.2.2 HMM system ............................................................................................................... 11 1.3 Dissertation overview ......................................................................................................... 13 CHAPTER 2 Waveguide Lithography Utilizing Single High-k Mode ....................................... 15 2.1 Spatial frequency selection ................................................................................................. 15 2.2 Waveguide lithography ....................................................................................................... 18 2.2.1 Design of waveguide lithography ................................................................................ 18 2.2.2 Waveguide mode analyses ........................................................................................... 22 2.3 Fabrication and experimental setup .................................................................................... 24 2.3.1 Nanofabrication of mask and substrate ........................................................................ 24 iv 2.3.2 Exposure system .......................................................................................................... 25 2.4 Results and discussions ....................................................................................................... 27 2.4.1 Experimental conditions .............................................................................................. 27 2.4.2 Partially polarized light ................................................................................................ 29 2.4.3 Double exposure .......................................................................................................... 30 2.4.4 Applications ................................................................................................................. 30 2.5 Other cases .......................................................................................................................... 33 2.5.1 Effects of film roughness ............................................................................................. 33 2.5.2 Waveguide lithography at 365 nm and 436 nm ........................................................... 34 2.5.3 Extremely small patterns using 193 nm and 248 nm light........................................... 35 2.5.4 Using high-index dielectrics for lithography ............................................................... 36 2.5.5 Comparison with direct contact lithography ................................................................ 37 2.6 Plasmonic roller system ...................................................................................................... 38 2.6.1 Design principle of plasmonic roller system ............................................................... 39 2.6.2 Fabrication of the flexible mask and experimental setup ............................................ 40 2.6.3 Stress on the roller system ........................................................................................... 42 2.6.4 Results and discussions ................................................................................................ 44 2.7 Summary ............................................................................................................................. 45 CHAPTER 3 Interference Lithography Based on ENZ HMM .................................................... 47 3.1 Lithography system using HMM ........................................................................................ 47 v 3.1.1 ENZ HMM lithography system using Al..................................................................... 49 3.1.2 ENZ HMM lithography system using Ag .................................................................... 51 3.2 Principle of ENZ HMM ...................................................................................................... 53 3.2.1 Surface wave ................................................................................................................ 53 3.2.2 Waveguide modes ........................................................................................................ 55 3.2.3 Type I and II ENZ HMM ............................................................................................. 60 3.2.4 Direction of the light propagation ................................................................................ 62 3.2.5 Mode coupling in the HMM ........................................................................................ 66 3.2.6 Loss of the ENZ waveguide mode ............................................................................... 67 3.3 Lithography design using ENZ HMM ................................................................................ 68 3.4 Experiment and discussion ................................................................................................. 72 3.5 Analyses
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